The present invention relates to amplifiers and, more particularly, to power amplifiers for use with radio frequency transceivers.
In prior art communication systems, transceivers are generally constructed to have transmitters with radio frequency outputs of limited power. In particular, in many very high frequency (VHF, 30-88 MHz) communication transceivers, the transmitters have a limited power output in the range of 5-10 watts. As will be appreciated, such fixer power output limits the versatility of the transceiver in different operational environments where greater output may be required.
Although it is apparent that the output of such transceivers can be boosted by use of power amplifiers, the actual implementation to achieve such amplification is not straightforward. In particular, different makes and types of communication transceivers have varying requirements which restrict their use without special modification. Specifically, the interface and control circuitry necessary for cooperation of a particular amplifier with an identified transceiver may be complex in construction and thereafter limited to only one type of transceiver. As a result, multiple amplifier designs and modifications would be required in order to address all types of communication transceivers for which increased power output is desired.
By way of example, numerous communication systems currently employ a frequency hopping capability to allow its reliable use in an interference environment. As a result, the construction of the transceiver to accomplish that frequency hopping is inherently more complex in operation and control. In order to provide an amplifier capable of being compatible with such frequency hopping capabilty, the same must meet the hopping requirements and interface with the required controls and interface structures of the particular transceivers. Due to the variety of frequency hopping designs, power amplifiers for such systems are normally specifically tailored to the particular communication system. There is therefore a continuing need for amplifier designs and construction which allow amplifier use with a variety of communication transceivers to thereby extend the versatility of the amplifiers and transceivers.
Accordingly, the present invention has been developed to overcome the specific shortcomings of the above known and similar techniques, and to provide a radio frequency power amplifier system which is compatible with different communication systems.